From bb728b7132ee79b2ab0243ac03b154e1a02b4fc6 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Sat, 20 Jan 2018 12:20:29 +0100
Subject: [PATCH 3/4] drm: Reset primary plane rotation to DRM_MODE_ROTATE_0

On devices where the (LCD) panel is mounted upside-down in the case
the kernel's drm_fb_helper code may have set up rotation on the primary
plane to make the text-console (and other fbdev using apps) show the right
way up.

We inherit this rotation from the text-mode and since we do our own rotation
where necessary we end up rotating twice and showing the boot-splash
upside-down again.

Dealing with hardware rotation may require using a specific framebuffer
tiling which we do not support, so we should just disable the hardware
rotation and keep using our own software rotation.

This commit adds code to find the primary plane and its rotation property
and if it is not DRM_MODE_ROTATE_0 then sets it to DRM_MODE_ROTATE_0. fixing
the double rotation issue.
---
 src/plugins/renderers/drm/plugin.c | 86 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/src/plugins/renderers/drm/plugin.c b/src/plugins/renderers/drm/plugin.c
index f495854..d3217ec 100644
--- a/src/plugins/renderers/drm/plugin.c
+++ b/src/plugins/renderers/drm/plugin.c
@@ -43,6 +43,7 @@
 #include <unistd.h>
 
 #include <drm.h>
+#include <drm_mode.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 
@@ -62,6 +63,11 @@
 
 #define BYTES_PER_PIXEL (4)
 
+/* For builds with libdrm < 2.4.89 */
+#ifndef DRM_MODE_ROTATE_0
+#define DRM_MODE_ROTATE_0 (1<<0)
+#endif
+
 struct _ply_renderer_head
 {
         ply_renderer_backend_t *backend;
@@ -499,6 +505,85 @@ ply_renderer_head_free (ply_renderer_head_t *head)
         free (head);
 }
 
+static void
+ply_renderer_head_clear_plane_rotation (ply_renderer_backend_t *backend,
+                                        ply_renderer_head_t    *head)
+{
+        drmModeObjectPropertiesPtr plane_props;
+        drmModePlaneResPtr plane_resources;
+        drmModePropertyPtr prop;
+        drmModePlanePtr plane;
+        uint64_t rotation;
+        uint32_t i, j;
+        int rotation_prop_id = -1;
+        int primary_id = -1;
+        int err;
+
+        err = drmSetClientCap (backend->device_fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
+        if (err)
+                return;
+
+        plane_resources = drmModeGetPlaneResources (backend->device_fd);
+        if (!plane_resources)
+                return;
+
+        for (i = 0; i < plane_resources->count_planes; i++) {
+                plane = drmModeGetPlane (backend->device_fd,
+                                         plane_resources->planes[i]);
+                if (!plane)
+                        continue;
+
+                if (plane->crtc_id != head->controller_id) {
+                        drmModeFreePlane (plane);
+                        continue;
+                }
+
+                plane_props = drmModeObjectGetProperties (backend->device_fd,
+                                                          plane->plane_id,
+                                                          DRM_MODE_OBJECT_PLANE);
+
+                for (j = 0; plane_props && (j < plane_props->count_props); j++) {
+                        prop = drmModeGetProperty (backend->device_fd,
+                                                   plane_props->props[j]);
+                        if (!prop)
+                                continue;
+
+                        if (strcmp (prop->name, "type") == 0 &&
+                            plane_props->prop_values[j] == DRM_PLANE_TYPE_PRIMARY) {
+                                primary_id = plane->plane_id;
+                        }
+
+                        if (strcmp (prop->name, "rotation") == 0) {
+                                rotation_prop_id = plane_props->props[j];
+                                rotation = plane_props->prop_values[j];
+                        }
+                        
+                        drmModeFreeProperty (prop);
+                }
+
+                drmModeFreeObjectProperties (plane_props);
+                drmModeFreePlane (plane);
+
+                if (primary_id != -1)
+                        break;
+
+                /* Not primary -> clear any found rotation property */
+                rotation_prop_id = -1;
+        }
+
+        if (primary_id != -1 && rotation_prop_id != -1 && rotation != DRM_MODE_ROTATE_0) {
+                err = drmModeObjectSetProperty (backend->device_fd,
+                                                primary_id,
+                                                DRM_MODE_OBJECT_PLANE,
+                                                rotation_prop_id,
+                                                DRM_MODE_ROTATE_0);
+                ply_trace ("Cleared rotation on primary plane %d result %d",
+                           primary_id, err);
+        }
+
+        drmModeFreePlaneResources (plane_resources);
+}
+
 static bool
 ply_renderer_head_set_scan_out_buffer (ply_renderer_backend_t *backend,
                                        ply_renderer_head_t    *head,
@@ -525,6 +610,7 @@ ply_renderer_head_set_scan_out_buffer (ply_renderer_backend_t *backend,
                 return false;
         }
 
+        ply_renderer_head_clear_plane_rotation (backend, head);
         return true;
 }
 
-- 
2.14.3